/*
 * Copyright 2011 James Moger.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.iciql;

import com.iciql.TableDefinition.FieldDefinition;
import com.iciql.TableDefinition.IndexDefinition;
import com.iciql.util.StatementBuilder;

/**
 * H2 database dialect.
 */
public class SQLDialectH2 extends SQLDialectDefault {

    /**
     * CACHED tables are created by default. MEMORY tables are created upon
     * request.
     */
    @Override
    protected <T> String prepareCreateTable(TableDefinition<T> def) {
        if (def.memoryTable) {
            return "CREATE MEMORY TABLE IF NOT EXISTS";
        } else {
            return "CREATE CACHED TABLE IF NOT EXISTS";
        }
    }

    @Override
    protected <T> String prepareCreateView(TableDefinition<T> def) {
        return "CREATE VIEW IF NOT EXISTS";
    }

    @Override
    public <T> void prepareDropView(SQLStatement stat, TableDefinition<T> def) {
        StatementBuilder buff = new StatementBuilder("DROP VIEW IF EXISTS "
                + prepareTableName(def.schemaName, def.tableName));
        stat.setSQL(buff.toString());
        return;
    }

    @Override
    protected boolean prepareColumnDefinition(StatementBuilder buff, String dataType,
                                              boolean isAutoIncrement, boolean isPrimaryKey) {
        String convertedType = convertSqlType(dataType);
        boolean isIdentity = false;
        if (isIntegerType(dataType)) {
            if (isAutoIncrement && isPrimaryKey) {
                buff.append("IDENTITY");
                isIdentity = true;
            } else if (isAutoIncrement) {
                buff.append(convertedType);
                buff.append(" AUTO_INCREMENT");
            } else {
                buff.append(convertedType);
            }
        } else {
            buff.append(convertedType);
        }
        return isIdentity;
    }

    @Override
    public void prepareCreateIndex(SQLStatement stat, String schema, String table, IndexDefinition index) {
        StatementBuilder buff = new StatementBuilder();
        buff.append("CREATE ");
        switch (index.type) {
            case STANDARD:
                break;
            case UNIQUE:
                buff.append("UNIQUE ");
                break;
            case HASH:
                buff.append("HASH ");
                break;
            case UNIQUE_HASH:
                buff.append("UNIQUE HASH ");
                break;
        }
        buff.append("INDEX IF NOT EXISTS ");
        buff.append(index.indexName);
        buff.append(" ON ");
        buff.append(table);
        buff.append("(");
        for (String col : index.columnNames) {
            buff.appendExceptFirst(", ");
            buff.append(col);
        }
        buff.append(")");
        stat.setSQL(buff.toString());
    }

    @Override
    public <T> void prepareMerge(SQLStatement stat, String schemaName, String tableName,
                                 TableDefinition<T> def, Object obj) {
        StatementBuilder buff = new StatementBuilder("MERGE INTO ");
        buff.append(prepareTableName(schemaName, tableName)).append(" (");
        buff.resetCount();
        for (FieldDefinition field : def.fields) {
            buff.appendExceptFirst(", ");
            buff.append(field.columnName);
        }
        buff.append(") KEY(");
        buff.resetCount();
        for (FieldDefinition field : def.fields) {
            if (field.isPrimaryKey) {
                buff.appendExceptFirst(", ");
                buff.append(field.columnName);
            }
        }
        buff.append(") ");
        buff.resetCount();
        buff.append("VALUES (");
        for (FieldDefinition field : def.fields) {
            buff.appendExceptFirst(", ");
            buff.append('?');
            Object value = def.getValue(obj, field);
            Object parameter = serialize(value, field.typeAdapter);
            stat.addParameter(parameter);
        }
        buff.append(')');
        stat.setSQL(buff.toString());
    }

    @Override
    public <T, A> void prepareBitwiseAnd(SQLStatement stat, Query<T> query, A x, A y) {
        stat.appendSQL("BITAND(");
        query.appendSQL(stat, null, x);
        stat.appendSQL(",");
        query.appendSQL(stat, x, y);
        stat.appendSQL(")");
    }

    @Override
    public <T, A> void prepareBitwiseXor(SQLStatement stat, Query<T> query, A x, A y) {
        stat.appendSQL("BITXOR(");
        query.appendSQL(stat, null, x);
        stat.appendSQL(",");
        query.appendSQL(stat, x, y);
        stat.appendSQL(")");
    }

}